Few = 2
Sevral = 3 or more
Well from reading those reviews myself I gathered the following.
moscart and King arms ones are pretty much identical in both looks, function and parts. Pain in the ass because of the bearings as you already stated. From personal experience they are pretty powerfull, and if loaded properly with care the bearings are not that big of an issue.
Madbull ones I have no personal experience with, but according to the reviews and comparisoms on Arnies are fuctionally a lot easier to use. dont have all the little bearing issues, and look a hell of a lot sexier. although they tend to be a little less on the power side, they make up for a lot more function and ease of reload to make it worth while.
Not sure who else makes them other then those 3 (which are the most common ones out there). but I did a quick Search while back on Arnies rereading the reviews and found this as well:
ICS Nade: http://arniesairsoft.co.uk/index.php...rom=&go=search
Found here on ASC:
Several good inputs from players about a few of the nades available on the market.